The UK has seen the biggest fall in millionaire numbers of any nation, says property consultancy Astons, using UBS Global Wealth Report 2025 data.

Millionaire numbers in the UK fell 14.3% in the past year and although the UK still boasts 4.4% of the world’s millionaires – some 2.6m individuals – the 12-month fall was worse than any other country. 

The US, China, France, Japan and Germany hold the largest shares of the world’s millionaires – 39.7%, 10.5%, 4.8%, 4.6% and 4.5% respectively – while millionaire numbers in Mexico, Brazil and Russia have grown markedly by 20.3%, 13.8% and 11.6%. 

Only five other countries – Australia, Japan, Saudi Arabia, Taiwan and Germany – saw any reduction in millionaire numbers. 

Astons attributes this downturn to the Labour government’s more aggressive taxation policies, especially against Non-Doms. 

Residency-by-investment schemes – the so-called Golden Visas – are becoming increasingly popular, says Astons, with Greece considered particularly attractive because of its accessible investment thresholds, Schengen Area access, and favourable legal frameworks.

Suzanna Uzakova, senior consultant for residency and citizenship programmes at Astons, says: “The significant decline in the number of UK millionaires is indicative of a broader trend where high-net-worth individuals are seeking more favourable tax environments.

“Recent UK tax reforms, such as changes to inheritance tax, capital gains tax, and the non-domiciled regime, have prompted many to reconsider their residency.

“Wealth is increasingly mobile, and countries like Greece offer structured and appealing alternatives.

“Greece’s Golden Visa programme remains one of Europe’s most attractive options, with a minimum investment of €250,000 required for properties converted from commercial to residential use.

“This threshold applies regardless of the property’s location, making it accessible even in high-demand areas.

“Additionally, the programme provides the benefit of Schengen Area access, a stable legal framework, and a high quality of life, all of which contribute to its growing popularity among relocating investors.”